Slip-on coupling gasket

Abstract

An annular gasket includes an annular body and an annular body and a pair of sealing ribs extending substantially radially inward from the annular body, each sealing rib having a sealing ridge, the sealing ridge of each of the pair of sealing ribs having a sealing surface, wherein the sealing surface is about cylindrical at rest.

That which is claimed is: 
     
       1. A pipe coupling system comprising:
 a first pipe having an outermost surface; 
 a second pipe having an outermost surface; and 
 a coupling comprising:
 a coupling segment; and 
 an annular gasket comprising:
 an annular body; and 
 a pair of sealing ribs extending substantially radially inward from the annular body, each sealing rib increasing in axial thickness from the annular body to a radially inward end of each sealing rib radially inside from the annular body, each sealing rib having a sealing ridge connected to the radially inward end thereof, each sealing ridge having a sealing surface, each sealing ridge decreasing in axial thickness from the radially inward end of each sealing rib to the sealing surface of each sealing ridge, 
 
 
 wherein the sealing surface of each sealing ridge is coannular in an undeformed state, the sealing surface of each sealing ridge having a diameter greater than a diameter of the outermost surface of the first pipe and a diameter of the outermost surface of the second pipe, 
 wherein in the undeformed state the annular gasket is configured to slide over the diameters of the outermost surfaces of the first pipe and the second pipe without contacting the outermost surfaces of the first pipe and the second pipe. 
 
     
     
       2. The pipe coupling system of  claim 1 , wherein the pair of sealing ribs extend from side portions of the annular body. 
     
     
       3. The pipe coupling system of  claim 1 , wherein each sealing rib includes an outer surface and wherein an angle drawn between the outer surface of each sealing rib and a radial direction is between 19° and 22°. 
     
     
       4. The pipe coupling system of  claim 1 , wherein each sealing ridge includes an axially outer drafted edge. 
     
     
       5. The pipe coupling system of  claim 4 , wherein the axially outer drafted edge of each sealing ridge extends from an axially exterior edge of each of the sealing surfaces of each sealing ridge. 
     
     
       6. The pipe coupling system of  claim 1 , wherein each sealing ridge includes an axially inner drafted edge. 
     
     
       7. The pipe coupling system of  claim 6 , wherein each axially inner drafted edge extends from an axially interior edge of each of the sealing surfaces of each sealing ridge. 
     
     
       8. The pipe coupling system of  claim 1 , further comprising a center rib extending radially inward from the annular body, wherein the center rib decreases in axial thickness from radially outside to radially inside. 
     
     
       9. The pipe coupling system of  claim 1 , wherein each of the first pipe and the second pipe includes a flare. 
     
     
       10. The pipe coupling system of  claim 1 , wherein at least one of the first pipe and the second pipe comprises conically flared ends. 
     
     
       11. A pipe coupling system comprising:
 a first pipe having an outermost surface; 
 a second pipe having an outermost surface; and 
 a coupling comprising
 a coupling segment; and 
 an annular gasket having an innermost diameter greater than a diameter of the outermost surface of the first pipe and a diameter of the outermost surface of the second pipe, the annular gasket comprising:
 an annular body; and 
 a pair of sealing ribs extending substantially radially inward from the annular body, each sealing rib increasing in axial thickness from the annular body to a radially inward end of each sealing rib radially inside from the annular body, each sealing rib having a sealing ridge connected to the radially inward end thereof, each sealing ridge having a sealing surface, each sealing ridge decreasing in axial thickness from the radially inward end of each sealing rib to the sealing surface of each sealing ridge, each sealing ridge having an axially outer drafted edge angled at a non-zero angle with respect to a radial axis perpendicular to a main axis of revolution of the annular gasket, 
 
 
 wherein in an undeformed state the annular gasket is configured to slide over the diameters of the outermost surfaces of the first pipe and the second pipe without contacting the outermost surfaces of the first pipe and the second pipe. 
 
     
     
       12. The pipe coupling system of  claim 11 , wherein each axially outer drafted edge is conical. 
     
     
       13. The pipe coupling system of  claim 11 , wherein an angle between each axially outer drafted edge and the radial axis is between 27° and 28°. 
     
     
       14. The pipe coupling system of  claim 11 , wherein each sealing ridge includes an axially inner drafted edge. 
     
     
       15. The pipe coupling system of  claim 14 , wherein the axially inner drafted edge of each sealing ridge is conical. 
     
     
       16. The pipe coupling system of  claim 11 , wherein each sealing ridge extends axially inwardly from the radially inward end of each sealing rib. 
     
     
       17. The pipe coupling system of  claim 16 , wherein the sealing surface of each sealing ridge is cylindrical in the undeformed state. 
     
     
       18. The pipe coupling system of  claim 11 , wherein the pair of sealing ribs each include an outer surface and wherein an angle between the outer surface of each sealing rib and the radial axis is between 19° and 22°. 
     
     
       19. The pipe coupling system of  claim 11 , wherein the axially outer drafted edge of each sealing ridge extends from the radially inward end of each sealing rib to the sealing surface of each sealing ridge, and wherein each radially inward end is axially and radially outside compared to each of the sealing surfaces. 
     
     
       20. The pipe coupling system of  claim 19 , wherein the sealing surface of each sealing ridge are coannular in the undeformed state. 
     
     
       21. The pipe coupling system of  claim 11 , wherein each of the first pipe and the second pipe includes a flare. 
     
     
       22. The pipe coupling system of  claim 11 , wherein at least one of the first pipe and the second pipe comprises a conical flare.